1. Field of the Invention
The present invention relates to a dental separator ring that may be used in methods for the restoration of a decayed portion of a tooth.
2. Description of the Related Art
Dental cavities that have spread to the dentin or have undergone cavitation are typically treated by removing the decayed portion of the tooth and thereafter filling the missing tooth structure with a restorative material such as silver (amalgam), white (polymeric resin), porcelain, or gold. Cavities that are located adjacent to neighboring teeth are called interproximal cavities.
When treating interproximal cavities, the dentist first removes the decayed portion of the side of the tooth. In order to properly deposit the restorative material on the side of the tooth without undesired leaking of the restorative material beyond the side of the tooth, the dentist places a dental matrix around at least a portion of the tooth. The dental matrix may be a metallic or plastic strip, and when the matrix is placed around at least a portion of the tooth, the matrix acts as a form for the desired shape of the restored tooth. Various dental matrices and methods are shown in U.S. Patent Application Publication Nos. 2008/0064012 and 2008/0064003. (These patents and all other patents and publications cited herein are incorporated herein by reference.)
A dental separator ring may also be used when filling interproximal cavities. The separator ring applies pressure against the adjacent teeth to force the adjacent teeth apart to allow a dental matrix to be positioned between the adjacent teeth. The dental separator ring may also include specially configured ends that also function as a matrix stabilizer that maintains the matrix and any other matrix stabilizer in a desired position with respect to the tooth to be restored. Example dental separator rings can be found in U.S. Pat. Nos. 7,284,983, 6,325,625, 6,206,697 and 5,607,302 and U.S. Patent Application Publication Nos. 2008/0064009, 2007/0172793 and 2005/0147941.
The device of U.S. Pat. No. 7,284,983 has disadvantages. For example, the wedge shaped engager can make a flat spot when more of the tooth is missing. Another concern is that the angle of pressure may be less separating mesial-distal (front-back) and more buccal-lingual which will not spread the teeth as much.
The device of U.S. Pat. No. 5,607,302 also has disadvantages. For example, the sharp point on the mid-interproximal runs into the dental matrix and can make a flat spot. Also, the device focuses pressure in the middle between occlusal and gingival. Additionally, the pointed and arcing area in general encroaches in the interproximal area and will not allow the dental matrix to expand fully from buccal to lingual so as to reach out and create a solid contact on a tough contact or diastema case. Thus, the device does not allow the whole matrix to arc out. The resultant marginal ridge/contact area can be unhygienic. It will also be prone to fracture because it is too narrow from buccal to lingual, first because of the reduction in total volume of composite filling material, and secondly because the protection (buttressing) of the neighboring marginal ridge is not fully utilized. Also, the shape of the device can smash a traditional wedge.
Therefore, although various dental separator rings are available, there is still a need for an improved dental separator ring that may be used in the restoration of a decayed portion of a tooth.